Emitter, manufacturing method and manufacturing apparatus thereof, electro-optical apparatus and electronic apparatus

ABSTRACT

An emitter has a plurality of type of light-emitting units with different changes in emission chracteristics over time. In addition, the emitter includes a deterioration adjustment device which adjusts the deterioration of the emission characteristics over time in a predetermined type of light-emitting unit. The light-emitting units respectvely include a light-emittig unit layer and a donor which supplies positive holes to the light-emiting layer, and deterioration adjustment device may be the hole donor in which the thickness is adjustadle based on the deterioration in emission characteristics over time in the predetermined type of light-emitting unit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional patent application of U.S. Ser. No.11/436,183 filed May 17, 2006 which is a divisional of U.S. Ser. No.10/760,178 filed Jan. 19, 2004, now U.S. Pat. No. 7,071,486, whichclaims priority to Japanese Application No. 2004-003754 filed Jan. 9,2004 and Japanese Application No. 2003-018776 filed Jan. 28, 2003, allof which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an emitter, a manufacturing method anda manufacturing apparatus thereof, an electro-optical apparatus and anelectronic apparatus.

2. Description of Related Art

Various emitters such as displays and light sources using self-emittingdevices in the form EL devices (and particularly organic EL devices)have been proposed in the past, and among these emitters, an organic ELdisplay apparatus is also known that is capable of displaying colors.During the production of an organic EL device, for example, a materialthat forms a light-emitting layer and a material that forms a positivehole injection (PEDOT)/electron transport layer are used as ink, andeach material is patterned on a device substrate such as a TFT by red,green and blue ink using an inkjet method to produce a self-emittingfull-color EL device, and this technology is disclosed in JapaneseUnexamined Patent Application, First Publication No. H10-12377 andJapanese Unexamined Patent Application, First Publication No.H10-153967.

In order to perform color display with this type of organic EL displaydevice, a single pixel is normally composed with an organic EL device(light-emitting unit) that emits red light, an organic EL device(light-emitting unit) that emits green light, and an organic EL device(light-emitting unit) that emits blue light corresponding to the threeprimary colors of light in the form of red (R), green (G) and blue (B).For example, in the case of making an arbitrary pixel bright white, eachof the red, green and blue organic EL devices that compose the pixelshould all be made to emit light. In addition, by suitably controllingthe emission brightness of each red, green and blue organic EL devicethat compose a pixel, an arbitrary pixel can be made to emit light of adesired color and brightness. In the case of performing color displayusing the three colors of organic EL devices as mentioned above, it isknown to be important to ensure satisfactory white balance.

However, conventionally, there are problems like those described below.

Although a product is able to maintain satisfactory white balanceimmediately after being shipped, due to differences in the deteriorationcharacteristics of the red, green and blue light-emitting materials overtime, the white balance breaks down due to changes in each color overtime. Thus, even when a predetermined current is supplied to eachorganic EL device with the intention of emitting white light, the actualcolor is not an attractive white color, and even if another arbitrarycolor is attempted to be emitted at an arbitrary brightness, there wasthe problem of again not being able to obtain the intended emittedcolor.

In consideration of the aforementioned problems, the object of thepresent invention is to provide an emitter allowing the obtaining of asatisfactory emission state even if there are changes over time in anemitter (e.g., EL apparatus) composed by containing a plurality of typesof light-emitting units (e.g., EL devices) having different changes inemission characteristics over time, a manufacturing method andmanufacturing system of this emitter, an electro-optical apparatus andelectronic apparatus.

SUMMARY OF THE INVENTION

The present invention employs the following constitution to achieve theaforementioned object.

The first aspect of the present invention is an emitter having aplurality of types of light-emitting units with different changes inemission characteristics over time, comprising a deteriorationadjustment device which adjusts the deterioration of the emissioncharacteristics over time in a predetermined type of light-emittingunit.

According to this aspect, by adjusting the deterioration of emissioncharacteristics over time in a predetermined type of light-emitting unitto match the deterioration over time in another light-emitting unit, thestate of deterioration between the plurality of types of light-emittingunits can be made to be the same even if changes in emissioncharacteristics occur over time, thereby making it possible to maintaina constant color balance by the plurality of types of light-emittingunits.

In the case of the light-emitting units respectively having alight-emitting layer and a hole donor which supplies positive holes tothe light-emitting layer, a constitution can be employed that uses forthe deterioration adjustment device a hole donor in which the thicknessis adjusted based on the deterioration in emission characteristics overtime in the aforementioned predetermined type of light-emitting unit. Inaddition, in the case the light-emitting units respectively have alight-emitting layer and an electron donor which supplies electrons tothe light-emitting layer, a constitution can be employed that uses forthe deterioration adjustment device an electron donor in which thethickness is adjusted based on the deterioration of emissioncharacteristics over time in the aforementioned predetermined type oflight-emitting unit. Moreover, in the case the light-emitting unitsrespectively have a light-emitting layer and a hole donor which suppliespositive holes to the light-emitting layer, a constitution can beemployed that uses for the deterioration adjustment device at least oneof either the aforementioned light-emitting layer and the aforementionedhole donor into which impurities are mixed based on the deterioration ofemission characteristics over time in the aforementioned predeterminedtype of light-emitting unit.

A constitution can be employed for the deterioration adjustment devicewhich adjusts the deterioration of emission characteristics over time inthe predetermined type of light-emitting unit according to thelight-emitting unit among the aforementioned plurality of types oflight-emitting units that has the largest degree of deterioration ofemission characteristics over time.

As a result, since a light-emitting unit having a large degree ofdeterioration of emission characteristics over time can be made to matcha light-emitting unit having a small degree of deterioration of emissioncharacteristics over time by adjusting the deterioration over time, thestate of deterioration between the plurality of types of light-emittingunits can be made to be the same even if changes in emissioncharacteristics occur over time, thereby making it possible to maintaina constant color balance by the plurality of types of light-emittingunits.

The second aspect of the present invention is an electro-opticalapparatus having the aforementioned emitter as display apparatus.

According to this aspect, the present invention allows the obtaining ofan electro-optical apparatus capable of displaying a satisfactoryemission state even if changes occur over time.

The third aspect of the present invention is an electronic apparatushaving the aforementioned emitter as display apparatus.

According to this aspect, the present invention allows the obtaining ofelectronic apparatus capable of displaying a satisfactory emission stateeven if changes occur over time.

The fourth aspect of the present invention is a manufacturing method ofan emitter having a plurality of types of light-emitting units withdifferent changes in emission characteristics over time, the methodhaving a deterioration adjustment step of adjusting deterioration of theemission characteristics over time in a predetermined type oflight-emitting unit.

The fifth aspect of the present invention is a manufacturing apparatusof an emitter having a plurality of types of light-emitting units withdifferent changes in emission characteristics over time, the apparatuscomprising a deterioration adjustment device which adjusts deteriorationof the emission characteristics over time in a predetermined type oflight-emitting unit.

According to this aspect, by matching the deterioration of emissioncharacteristics over time in a predetermined type of light-emitting unitto the deterioration over time in another light-emitting unit byadjusting the deterioration over time, the deterioration state betweenthe plurality of types of light-emitting units can be made to be thesame even if changes occur in emission characteristics over time,thereby making it possible to maintain a constant color balance by theplurality of types of light-emitting units.

In the case the light-emitting units respectively have a light-emittinglayer and a hole donor which supplies positive holes to thelight-emitting layer, the thickness of the hole donor is preferablyadjusted in the deterioration adjustment step or deteriorationadjustment device based on the deterioration of emission characteristicsover time in the predetermined type of light-emitting unit.

In this case, by thinly forming the hole donor in the light-emittingunit in which the degree of deterioration over time is small as comparedwith that of another light-emitting unit, for example, the degree ofdeterioration over time can be increased, thereby making it possible tomake the deterioration state between the plurality of types oflight-emitting units the same.

In addition, in the case of having a discharge step or discharge devicewhich forms a hole donor by discharging a liquid containing a hole donormaterial, a constitution is employed in the deterioration adjustmentstep or deterioration adjustment device which adjusts the weight or thenumber of drops of the liquid discharged.

In this case, by adjusting the weight or number of drops of the liquiddischarged, for example, a hole donor can be thinly formed in apredetermined type of light-emitting unit having a small degree ofdeterioration over time.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the general appearance of amanufacturing apparatus according to the present invention.

FIGS. 2A to 2C are drawings showing the structure of an inkjet head.

FIG. 3 is a drawing schematically showing the constitution of an organicEL apparatus of the present invention.

FIG. 4 is a circuit drawing of an active matrix type of organic ELapparatus.

FIG. 5 is an enlarged view showing the cross-sectional structure of thedisplay area of an organic EL apparatus.

FIGS. 6A to 6D are explanatory drawings for explaining the manufacturingmethod of an organic EL apparatus.

FIG. 7 is a graph showing the relationship between white chromaticityand respective required brightness of R, G and B.

FIG. 8 is a graph showing the relationship between positive holetransport layer thickness and deterioration over time.

FIG. 9 is a perspective view showing a mobile personal computer as anexample of electronic apparatus equipped with an organic EL apparatus.

FIG. 10 is a perspective view showing a mobile telephone as an exampleof electronic apparatus equipped with an organic EL apparatus.

FIG. 11 is a perspective view showing a digital still camera as anexample of electronic apparatus equipped with an organic EL apparatus.

DETAILED DESCRIPTION OF THE INVENTION

The following provides an explanation of embodiments of an emitter ofthe present invention, a manufacturing method and manufacturingapparatus thereof, an electro-optical apparatus and electronic apparatuswith reference to FIGS. 1 to 11.

The present embodiment applies the present invention to a displayapparatus (organic EL display apparatus) in the form of an organic ELapparatus (emitter) capable of color display by having a single pixelwith three dots of an organic EL device capable of emitting red color(light-emitting unit), organic EL device capable of emitting green light(light-emitting unit) and organic EL device capable of emitting bluecolor (light-emitting unit). Furthermore, the scale in each of thereference drawings may differ for each layer and member in order to makethem of a legible size in the drawings.

(First Embodiment)

First, an explanation is provided of a manufacturing apparatus forproducing an EL apparatus.

FIG. 1 is a perspective view of the general appearance of a filmdeposition apparatus (inkjet apparatus) that composes an ELmanufacturing apparatus (device manufacturing apparatus). Filmdeposition apparatus 30 employs a constitution in which an ink to bedescribed later containing light-emitting materials and a positive holetransport material is discharged onto a substrate by an inkjet system.

Film deposition apparatus 30 has, among other components, a base 32, afirst movement unit 34, a second movement unit 16, an electronic balancenot shown (weighing unit), a liquid droplet discharge head in the formof inkjet head (discharge apparatus) 20, a capping unit 22 and acleaning unit 24. The first movement unit 34, electronic balance,capping unit 22, cleaning unit 24 and second movement unit 16 arerespectively arranged on base 32.

First movement unit 34 is preferably installed directly on base 32, andthis first movement unit 34 is positioned along the direction of the Yaxis. In contrast, the second movement unit 16 is attached perpendicularto base 32 using support columns 16A, and second movement 16 is alsoattached to rear section 32A of base 32. The direction of the X axis ofsecond movement unit 16 is perpendicular to the direction of the Y axisof first movement unit 34. The Y axis is the axis along the direction offront section 32A and rear section 32B of base 32. In contrast, the Xaxis is the axis along the left and right directions of base 32, and isrespectively horizontal.

First movement unit 34 has guide rails 40, and first movement unit 34can employ, for example, a linear motor. Slider 42 of this linear motortype of first movement unit 34 can be positioned by moving in thedirection of axis Y along guide rails 40. Table 46 positions a workpiecein the form of substrate 2 while also being able to maintain thatposition. In addition, table 46 has a suction holding unit 50 that iscapable of holding substrate 2 by suctioning onto table 46 through hole46A in table 46 due to the operation of suction holding unit 50. Apreliminary discharge area 52 is provided on table 46 for discardeddischarge or test discharge (preliminary discharge) of ink by inkjethead 20.

The second movement unit 16 has a column 16B fastened to support columns16A, and this column 16B has a linear motor type of second movement unit16. Slider 60 can be positioned by moving in the direction of axis Xalong guide rails 62A. Slider 60 is provided with an ink discharge unitin the form of inkjet head 20.

Slider 42 is provided with a θ axis motor 44. This motor is, forexample, a direct drive motor, and the rotor of motor 44 is fastened totable 46. As a result, by supplying power to motor 44, rotor and table46 rotate along the θ direction making it possible to index (rotate)table 46.

Inkjet head 20 has oscillating positioning units in the form of motors62, 64, 66 and 68. When motor 62 is operated, inkjet head 20 can bepositioned vertically along the Z axis. This Z axis is in a direction(vertical direction) that is perpendicular to the X axis and Y axis,respectively. When motor 64 is operated, inkjet head 20 can bepositioned by oscillating along the β direction about the Y axis. Whenmotor 66 is operated, inkjet head 20 can be positioned by oscillating inthe γ direction about the X axis. When motor 68 is operated, inkjet head20 can be positioned by oscillating in the a direction about the Z axis.

In this manner, since inkjet head 20 in FIG. 1 can be positioned bymoving directly in the direction of the Z axis on slider 60, and can bepositioned by oscillating along the α, β and γ directions, the locationor orientation of an ink discharge surface 20P of inkjet head 20 can beaccurately controlled relative to substrate 2 on table 46. Furthermore,a plurality (e.g., 120) of openings in the form of nozzles thatrespectively discharge ink are provided in ink discharge surface 20P ofinkjet head 20.

Here, an explanation is provided of an example of the structure ofinkjet head 20 with reference to FIGS. 2A to 2C.

Inkjet head 20 is a head that uses, for example, piezoelectric devices,and as shown in FIG. 2A, a plurality of nozzles 91 are formed in inkdischarge surface 20P of head body 90. Piezoelectric devices 92 areprovided for each of these nozzles 91.

As shown in FIG. 2B, piezoelectric devices 92 are arranged correspondingto nozzles 91 and ink chamber 93, are positioned between, for example, apair of electrodes (not shown), and are composed so as to bend so as toprotrude to the outside when power is supplied. As a result of applyingan applied voltage Vh to a piezoelectric device 92 as shown in FIG. 2C,piezoelectric device 92 expands and contracts in the direction of arrowQ thereby causing a liquid droplet (ink droplet) of a predeterminedvolume to be discharged from nozzle 91. The driving of thesepiezoelectric devices 92, namely the discharge of liquid droplets frominkjet head 20, is controlled by a deterioration adjustment device inthe form of control device 25 (see FIG. 1).

Returning to FIG. 1, the electronic balance receives, for example, 5000droplets from the nozzles of inkjet head 20 in order to manage theweight of a single droplet of ink discharged from the nozzles of inkjet20 by measuring its weight. The electronic balance is able to measurethe weight of a single ink droplet quite accurately by dividing theweight of these 5000 ink droplets by 5000. The amount of ink dropletsdischarged from inkjet head 20 can then be optically controlled based onthe measured weight of the ink droplets.

Continuing, an explanation is provided of a film deposition treatmentstep.

When a worker places a substrate 2 onto table 46 of first movement unit34 from the front end of table 46, this substrate 2 is positioned bybeing suctioned and held on table 46. Motor 44 operates to position theedge of substrate 2 so as to be parallel with the direction of the Yaxis.

Next, inkjet head 20 moves along the direction of the X axis and ispositioned above the electronic balance. A specified number of droplets(specified number of ink droplets) are then discharged. As a result, theelectronic balance measures the weight of, for example, 5000 droplets ofink, and calculates the weight per single ink droplet. A judgment isthen made as to whether the weight per ink droplet is within a presetproper range, and if it is outside this range, the voltage applied topiezoelectric devices 92 is adjusted so as to obtain a weight per inkdroplet that falls within the proper range.

In the case the weight per ink droplet is appropriate, together withsubstrate 2 being positioned by suitably moving in the direction of theY axis by first movement unit 34, inkjet head 20 is positioned bysuitably moving in the direction of the X axis by second movement unit16. After preliminarily discharging ink from all nozzles onto apreliminary discharge area 52, inkjet head 20 moves relatively in thedirection of the Y axis with respect to substrate 2 (in actuality,substrate 2 moves in the Y direction relative to inkjet head 20), anddischarges ink at a predetermined width from predetermined nozzles ontoa predetermined area on substrate 2 under the control of control system25. Once a single round of relative movement by inkjet head 20 andsubstrate 2 is completed, inkjet head 20 moves by being indexed by apredetermined amount in the direction of the X axis relative tosubstrate 2, after which it discharges ink during the time substrate 2moves relative to inkjet head 20. By then repeating this operation aplurality of times, ink is discharged over the entire film depositionarea on substrate 2 thereby making it possible to deposit a film.

Continuing, an explanation is provided of an organic EL apparatusaccording to the present invention with reference to FIGS. 3 to 6.

FIG. 3 shows an organic EL apparatus, and more particularly,schematically shows an embodiment in which the present invention isapplied to an active matrix type of organic EL apparatus. In addition,this organic EL apparatus (emitter) 1 employs an active type of drivesystem using a thin film transistor.

Organic EL apparatus 1 is composed by sequentially laminating a circuitdevice in the form of a circuit device section 14 that contains a thinfilm transistor, a pixel electrode (anode) 11, a functional layercontaining an organic EL layer (organic EL device), an electron donor inthe form of a cathode 12, and a sealing section 3 and so forth on asubstrate 2.

A glass substrate is used for substrate 2 in the present embodiment. Inaddition to a glass substrate, examples of other substrates that can beused in the present invention include a silicon substrate, quartzsubstrate, ceramic substrate, metal substrate, plastic substrate,plastic film substrate and various other known substrates used inelectro-optical apparatuses and circuit boards.

A plurality of pixel areas (light-emitting units) A are arranged in theform of a matrix on substrate 2 as light-emitting areas, and in the caseof color display, for example, pixel areas A corresponding to each ofthe colors of red (R), green (G) and blue (B) are arranged in apredetermined configuration. A pixel electrode 111 is arranged for eachpixel area A, and a signal line 132, power line 133, scanning line 131and scanning lines for other pixel electrodes not shown are arranged inthe vicinity thereof. In addition to the rectangular shape shown in thedrawings, a circular shape, oval shape or other arbitrary shape isapplied for the two-dimensional shape of pixel area A.

In addition, sealing section 3 prevents oxidation of cathode 12 orfunctional layer 10 by preventing the entrance of water and oxygen, andcontains a sealing resin coated onto substrate 2 and a sealing substrate3 b (package). Examples of materials of the sealing resin includethermosetting resins or ultraviolet-cured resins, and epoxy resin, whichis a type of thermosetting resin, is used preferably. The sealing resinis coated in the form of a ring around the periphery of substrate 2, andis applied with, for example, a microdispenser. Sealing substrate 3 b iscomposed of glass or metal, and substrate 2 and sealing substrate 3 bare laminated by means of sealing resin.

FIG. 4 shows the circuit structure of the aforementioned organic ELapparatus 1.

In FIG. 4, a plurality of scanning lines 131, a plurality of signallines 132 extending in a direction that intersects with scanning lines131, and a plurality of power lines 133 extending parallel to signallines 132 are wired on substrate 2. In addition, an aforementioned pixelarea A is formed at each intersection of scanning lines 131 and signallines 132.

A data drive circuit 103 containing, for example, a shift register,level shifter, video line and analog switch, is connected to signallines 132. In addition, a scanning drive circuit 104 containing a shiftregister and level shifter is connected to scanning lines 131.

A first thin film transistor 123 for switching, in which a scanningsignal is supplied to a gate electrode via scanning line 131, a holdingcapacitor 135 that holds the image signal supplied from signal line 132via this thin film transistor 123, a second thin film transistor 124 fordriving, in which the image signal held by holding capacitor 135 issupplied to a gate electrode, a pixel electrode (anode) 111, to whichdrive current from power line 133 flows when electrically connected topower line 133 via this thin film transistor 124, and a functional layer110, which is juxtaposed between pixel electrode 111 and a counterelectrode (cathode) 12, are provided in a pixel area A. Functional layer110 contains an organic EL device in the form of an organic EL layer.

In a pixel area A, when a scanning line 131 is driven and the first thinfilm transistor 123 is switched on, the potential of a signal line 132at that time is held by holding capacitor 135, and whether or notcurrent is supplied to the second thin film transistor 124 is determinedaccording to the state of this holding capacitor 135. In addition,current flows to pixel electrode 111 from power line 133 via a channelof the second thin film transistor 124, and current then flows tocounter electrode (cathode) 12 through functional layer 110. Functionallayer 110 then emits light corresponding to the amount of current atthis time.

FIG. 5 is an enlarged view of the cross-sectional structure of thedisplay area in the aforementioned organic EL apparatus 1. In this FIG.5, the cross-sectional structure is shown of three pixel areascorresponding to each of the colors of red (R), green (G) and blue (B).As was previously described, organic EL apparatus 1 is composed bysequentially laminating a circuit device section 14 in which is formed aTFT or other circuit, a pixel electrode (anode) 111, a light-emittingdevice 11 in which is formed functional layer 110, and a cathode 12 on asubstrate 2. In this organic EL apparatus 1, together with light emittedon the side of substrate 2 from functional layer 110 being radiated tothe lower side (observer side) of substrate 2 by passing through circuitdevice section 14 and substrate 2, light emitted on the opposite side ofsubstrate 2 from functional layer 110 is reflected by cathode 12 so asto be radiated to the lower side (observer side) of substrate 2 bypassing through circuit device section 14 and substrate 2.

An undercoating protective film 2c composed of a silicon oxide film isformed on substrate 2 in circuit device section 14, and an island-shapedsemiconductor film 141 composed of polycrystalline silicon is formed onthis undercoating protective film 2 c. Furthermore, a source region 141a and drain region 141 b are formed by high-concentration P ioninjection in semiconductor film 141. Furthermore, the section where P isnot injected serves as channel region 141 c. Moreover, a transparentgate insulting film 142 that covers undercoating protective film 2 c andsemiconductor film 141 is formed in circuit device section 14, a gateelectrode 143 (scanning line) composed of Al, Mo, Ta, Ti or W and soforth is formed on gate insulating film 142, and transparent firstinterlayer insulating film 144 a and second interlayer insulating film144 b are formed on gate electrode 143 and gate insulating film 142.Gate electrode 143 is provided at the location corresponding to channelregion 141 c of semiconductor film 141. In addition, contact holes 145and 146 are formed respectively connected to source and drain regions141 a and 141 b of semiconductor film 141 through first and secondinterlayer insulating films 144 a and 144 b.

A transparent pixel electrode 111 composed of ITO and so forth is formedby patterning to a predetermined shape on second interlayer insulatingfilm 144 b, and one of the contact holes 145 is connected to this pixelelectrode 111. In addition, the other contact hole 146 is connected topower line 133.

In this manner, a thin film transistor 123 connected to each pixelelectrode 111 is formed in circuit device section 14. Furthermore,although the aforementioned holding capacitor 135 and thin filmtransistor 124 for switching are also formed in circuit device section14, these are not shown in FIG. 5.

Light-emitting device 11 is mainly composed of functional layers 110respectively laminated on a plurality of pixel electrodes 111, and banksections 112 arranged between functional layers 110 that demarcate eachfunctional layer 110. A cathode 12 is arranged on each functional layer110. An organic EL device serving as a light-emitting device is composedby containing a pixel electrode 111, cathode 12, functional layer 110and so forth.

Here, a pixel electrode 111 is formed from ITO by patterning into aroughly rectangular shape when viewed from overhead. The thickness ofthis pixel electrode 111 is preferably within the range of 50-200 nm,and particularly preferably about 150 nm.

As shown in FIG. 5, a bank section 112 is composed by laminating aninorganic bank layer 112 a (first bank layer) located on the side ofsubstrate 2, and an organic bank layer 112 b (second bank layer) locatedaway from substrate 2. Inorganic bank layer 112 a is composed of aninorganic material such as SiO₂ or TiO₂. In addition, organic bank layer112 b is formed from a heat-resistant and solvent-resistant resist suchas acrylic resin or polyimide resin.

A functional layer 110 is composed of a hole donor in the form of apositive hole transport layer (positive hole injection/transport layer)110 a laminated on pixel electrode 111, and an organic EL layer(light-emitting layer) 110 b formed on positive hole transport layer 110a in contact therewith.

Together with having the function of injecting (supplying) positiveholes to organic EL layer 110 b, positive hole transport layer 110 a hasthe function of transporting positive holes within positive holetransport layer 110 a. By providing such a positive hole transport layer110 a between pixel electrode 111 and organic EL layer 110 b, emissionefficiency, service life and other device characteristics of organic ELlayer 110 b are improved. In addition, in organic EL layer 110 b,positive holes injected from positive hole transport layer 110 a andelectrons injected (supplied) from cathode 12 are re-coupled in theorganic EL layer resulting in the emission of light. Furthermore, amixture of, for example, a polythiophene derivative such as polyethylenedioxythiophene and polystyrene sulfonic acid and so forth can be usedfor the positive hole transport layer forming material.

Organic EL layer 110 b is composed of three types of layers havingmutually different emission wavelength bands consisting of a red organicEL layer 110 b 1 that emits red (R) light, a green organic EL layer 110b 2 that emits green (G) light, and a blue organic EL layer 110 b 3 thatemits blue (B) light, and each organic EL layer 110 b 1 through 110 b 3is arranged at a predetermined configuration (e.g., stripes).Furthermore, although the details will be described later, in thepresent embodiment, positive hole transport layers 110 a 1 and 110 a 2adjacent to red organic EL layer 110 b 1 and green organic EL layer 110b 2 are formed to have a film thickness thinner than positive holetransport layer 110 a 3 adjacent to blue organic EL layer 110 b 3.

Furthermore, an electron injection layer may be formed on organic ELlayer 110 a (on the side of cathode 12), and this may be included infunctional layer 110 as necessary. An electron injection layer has therole of promoting injection of electrons into organic EL layer 110 fromcathode 12, is formed by a lithium-quinolinol complex having lithium forthe central metal, and has a thickness preferably within the range of,for example, 2-5 nm, and particularly preferably about 2 nm. A materialother than a lithium-quinolinol complex may be used for the materialused for the electron injection layer, preferable examples of whichinclude complexes having metal elements selected from group 1A of theperiodic table, group 2A of the periodic table or rare earth elementssuch as Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu,Gd, Th, Dy, Ho, Er, Tm, Yb and Lu. An example of complex is sodiumquinolinol complex. In addition, the electron injection layer can beformed by preparing a composite ink in which the aforementionedlithium-quinolinol complex is dissolved in a liquid material to bedescribed later, and then discharged onto organic EL layer 110 b 3 by aliquid discharge method (inkjet method).

Cathode (counter electrode) 12 is formed over the entire surface oflight-emitting device 11, and forms a pair with pixel electrode 111 tofulfill the role of allowing current to flow to functional layer 110.This cathode 12 is capable of reducing lithium (Li) ions, and in thepresent embodiment, is composed by laminating calcium layer 12 a andaluminum layer 12 b. At this time, a cathode having a low workcoefficient is preferably provided for the cathode on the side close tothe light-emitting layer, and in this mode in particular, fulfills therole of injecting electrons into light-emitting layer 110 b by being indirect contact with light-emitting layer 110 b. The thickness of calciumlayer 12 a is, for example, preferably within the range of 2-50 nm. Inaddition, aluminum layer 12 b reflects light emitted from organic ELlayer 110 b to the side of substrate 2, and is preferably composed of anAg film or laminated Al and Ag film and so forth in addition to an Alfilm. In addition, the thickness of the aluminum layer 12 b is, forexample, preferably within the range of 100-1000 nm. Moreover, aprotective layer for preventing oxidation composed of SiO, SiO₂ or SiNand so forth may be provided on the aluminum layer.

Furthermore, although calcium (Ca) is used for the substance able toreduce lithium ions in the present embodiment, this substance is notlimited to calcium, but rather Mg or Al may also be used.

In the aforementioned constitution, a pixel electrode (anode) 111,positive hole transport layer 110 a, organic EL layer 110 b and cathode12 are laminated in that order from the side of substrate 2 in eachpixel area. In an organic EL apparatus 1 composed in this manner,calcium layer 12 a of cathode 12 fulfills the role of injectingelectrons into organic EL layer 110 b by being in direct contact withorganic EL layer 110 b in each color of organic EL layer 110 b.

In addition, an organic EL apparatus 1 of the present embodiment allowsthe obtaining of an equal degree of emission characteristics andemission service life when compared with the case of an organic ELapparatus provided with an electron injection layer formed using vapordeposition.

Next, an explanation is provided of a method for producing theaforementioned organic EL apparatus 1 with reference to FIGS. 6A to 6D.Furthermore, the circuit device section 14 containing a thin filmtransistor, the bank sections 112 (organic bank layers 112 a andinorganic bank layers 112 b) and the pixel electrodes 111 respectivelyshown in the previous FIG. 5 are assumed to have already been formed onsubstrate 2.

The manufacturing method of the present embodiment has a positive holetransport layer formation step, an organic EL layer formation step, acathode formation step and a sealing step and so forth.

Furthermore, the manufacturing method explained here is merely oneexample of a manufacturing method, and other steps may be omitted oradded as necessary.

(Positive Hole Transport Layer Formation Step)

As shown in FIG. 6A, a positive hole transport layer 110 a is formed onsubstrate 2 on which pixel electrodes are formed.

In the positive hole transport layer formation step, a composition(liquid droplets) containing a previously described positive holetransport layer forming material is discharged onto pixel electrodes 111by the aforementioned film deposition unit 30 using a liquid dischargemethod.

The procedure for forming the positive hole transport layer by a liquiddischarge method consists of filling a composite ink containing thematerial of positive hole transport layer 110 a into inkjet head 20 fordischarging a liquid, positioning the discharge nozzles of inkjet head20 to be in opposition to a pixel electrode 111 located in an opening ofbank sections 112, and discharging ink droplets, for which the amount ofliquid per droplet is controlled, from the nozzles while relativelymoving head 20 and substrate 2 (discharge step). Subsequently, the inkdroplets are subjected to drying treatment after being discharged, and apositive hole transport layer is formed by evaporating the polar solvent(liquid material) contained in the composite ink.

A composition in which, for example, a mixture of a polythiophenederivative such as polyethylene dioxythiophene (PEDOT) and polystyrenesulfonic acid (PSS) and so forth is dissolved in a polar solvent can beused for the composition used here. Examples of polar solvents includeisopropyl alcohol (IPA), normal butanol, γ-butyrolactone,N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazole (DMI and itsderivatives, as well as carbitol acetate, butyl carbitol acetate andother glycol ethers.

A specific example of a composition is 12.52 wt % PEDOT:PSS mixture(PEDOT/PSS =1:20), 1.44 wt % PSS, 10 wt % IPA, 27.48 wt % NMP and 50 wt% DMI. Furthermore, the viscosity of the composition is preferably about2-20 cPs, and particularly preferably about 4-15 cPs.

Here, in the present embodiment, in order to adjust deterioration ofemission characteristics over time for a plurality of colors (pluralityof types) of pixel regions for which the changes in emissioncharacteristics differ over time, the thickness of positive holetransport layer 110 a is changed corresponding to the degree of changesover time of each color. FIG. 7 shows a graph of the required brightnessof R, B and B in the case of plotting white chromaticity based on CIEchromaticity coordinates (0.33, 0.33). As shown in this graph, in orderto obtain a required brightness of 150 cd/m² with white brightness, forexample, brightness of 314 cd/m² for red, 629 cd/m² for green and 209cd/m² for blue are respectively required. In addition, in the case ofbeing only able to obtain white brightness of 100 cd/m² due todeterioration over time, brightness of 209 cd/m² for red, 419 cd/m² forgreen and 139 cd/m² for blue are respectively required. In other words,although it is possible to accommodate deterioration of white brightnessover time by increasing the voltage applied to the organic EL apparatus,in order to maintain white balance, it is necessary that thedeterioration over time of each of the colors of R, G and B becompatible.

FIG. 8 shows a graph of the relationship between the thickness ofpositive hole transport layers 110 a 1 to 110 a 3 corresponding to eachcolor and deterioration over time. As shown in this graph, in the caseof forming positive hole transport layers 110 al to 110 a 3 at the samethickness (here, 70 nm), the degree of deterioration of blue color islarger as compared with the other colors. Namely, in the case of causingorganic EL layers 110 b 1 to 110 b 3 to emit light using positive holetransport layers 110 a 1 to 110 a 3 having the same thickness, since theblue color deteriorates first, the color balance in a full-color panelshifts towards red and green color due to the deterioration of bluecolor over time. In response to this, in order to adjust thedeterioration of red and green color (predetermined types oflight-emitting units) over time while maintaining the film thickness ofblue color positive hole transport layer 110 a 3 at 70 nm, although thedeterioration of red and green color accelerates resulting in a decreasein service life if the film thicknesses of red color positive holetransport layer 110 a 1 and green color positive hole transport layer110 a 2 are made to be 50 nm, since the deterioration of R, G and B overtime is the same, color balance during full-color display can bemaintained constant. Furthermore, although the service lives of red andgreen color decrease, since these shortened service lives are made tomatch the service life of the blue color, there is no effect on theservice life of organic EL apparatus 1.

Thus, as a result of control system 25 controlling the driving ofpiezoelectric devices 92 in the positive hole transport layer formationstep, the droplet weight or number of droplets of the liquid droplets(liquid) discharged according to color are controlled so that the filmthickness of blue color positive hole transport layer 110 a 3 isultimately 70 nm, and the film thicknesses of red color positive holetransport layer 110 a 1 and green color positive hole transport layer110 a 2 are ultimately 50 nm (deterioration adjustment step). By thensubsequently carrying out drying treatment and heat treatment, positivehole transport layers 110 a 1 to 110 a 3 are formed on a pixel electrode111.

Furthermore, all following steps, including this positive hole transportlayer formation step, are preferably carried out in an atmosphere freeof water and oxygen. For example, the steps are preferably carried outin an inert gas atmosphere such as a nitrogen atmosphere or argonatmosphere.

(Organic EL Layer Formation Step)

Next, as shown in FIG. 6B, a blue color organic EL layer 110 b 3, forexample, is formed on blue color pixel electrode 111 on which islaminated positive hole transport layer 110 a. Namely, a composite inkcontaining an organic EL layer material is discharged onto positive holetransport layer 110 a by, for example, a liquid droplet discharge methodin the same manner as positive hole transport layer 110 a, and this isfollowed by drying treatment and heat treatment to form a blue colororganic EL layer 110 b 3 in an opening formed in bank sections 112.

In the organic EL layer formation step, in order to preventre-dissolution of positive hole transport layer 110 a, a non-polarsolvent in which positive hole transport layer 110 a is insoluble isused for the solvent of the composite ink used during formation of theorganic EL layer. In this case, a surface modification step ispreferably carried out prior to formation of the organic EL layer toenhance the wettability of the surface of positive hole transport layer110 a with respect to the non-polar solvent. A surface modification stepis carried out by, for example, coating the same solvent or similar typeof solvent as the aforementioned non-polar solvent onto positive holetransport layer 110 a by spin coating or dipping and so forth followedby drying. Furthermore, examples of surface modification solvents usedhere that are the same as the non-polar solvent of the composite inkinclude cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene andtetramethylbenzene, while examples of solvents that are of a similartype as the non-polar solvent of the composite ink include toluene andxylene.

In addition, the procedure for forming an organic EL layer by a liquiddroplet discharge method consists of filling inkjet head 20 with acomposite ink containing a material of, for example, a blue colororganic EL layer, positioning the discharge nozzles of inkjet head 20 tobe in opposition to a blue color positive hole transport layer 110 alocated in an opening of bank sections 112, and discharging inkdroplets, for which the amount of liquid per droplet is controlled, fromthe nozzles while relatively moving head 20 and substrate 2. Thedischarged ink droplets then spread over positive hole transport layer110 a and fill the openings of bank sections 112. Continuing, by thensubjecting the ink droplets to drying treatment after they have beendischarged, the non-polar solvent contained in the composite ink isevaporated resulting in the formation of blue color organic EL layer 110b 3. Subsequently, red color organic EL layer 110 b 1 and green colororganic EL layer 110 b 2 are formed using a composite ink containing amaterial for a red color EL organic layer and a composite ink containinga material for a green color organic EL layer in the same manner as bluecolor organic EL layer 110 b 3 (see FIG. 6A).

Furthermore, examples of light-emitting materials for composing organicEL layers 110 b include low molecular weight organic EL materials andhigh molecular weight organic EL materials soluble in fluorene-basedpolymer derivatives, (poly)paraphenylene vinylene derivatives,polyphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole,polythiophene derivatives, perylene-based pigments, coumarin-basedpigments, rhodamine-based pigments and other benzene derivatives.Examples of light-emitting materials that can be used include rubrene,perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red,coumarin 6 and quinacridone. On the other hand, non-polar solvents arepreferably those in which positive hole transport layer 110 a isinsoluble, and examples of non-polar solvents that can be used includecyclohexylbenzene, dihydrobenzofuran, trimethylbenzene andtetramethylbenzene.

Here, in addition to the aforementioned piezo method, examples of liquiddroplet discharge methods include electrostatic control, pressurizedvibration, thermoelectric conversion and electrostatic attraction. Inthe electrostatic control method, an electric charge is imparted to amaterial with a charged electrode and the material is discharged fromnozzles by controlling the direction of dispersal with a deflectingelectrode. In addition, in the pressurized vibration method, anultra-high pressure is applied to a material and the material isdischarged from the tips of nozzles such that material is dischargedfrom the nozzles in a straight line when a control voltage is notapplied, but is dispersed and not discharged from the nozzles due to theoccurrence of electrostatic repulsion between materials when a controlvoltage is applied. In addition, in the thermoelectric conversionmethod, the material is rapidly vaporized by a heater provided in achamber in which the material is stored to form bubbles, and thematerial within the chamber is then discharged according to the pressureof the bubbles. In the electrostatic attraction method, an extremely lowvoltage is applied inside a chamber in which a material is stored toform a meniscus of the material on the nozzles, and then the material isextracted after applying electrostatic attraction in this state. Inaddition, other technologies that can be applied include a method thatutilizes the change in viscosity of a fluid caused by a magnetic field,and a method that disperses a material with sparks generated from anelectrical discharge.

Among the aforementioned liquid droplet discharge technologies, thepiezo method offers the advantage of having little effect on thematerial composition since it does not involve the application of heatto the material.

(Cathode Formation Step)

Next, as shown in FIG. 6D, acounterelectrode(cathode) 12 is formed as apair with pixel electrode (anode) 111. Namely, cathode 12 is formed bysequentially laminating calcium layer 12 a and aluminum layer 12 b overthe entire area on substrate 2 that contains organic EL layer 110 b. Asa result, cathode 12 is laminated over the entire area of organic ELlayer 110 b containing the area in which red color organic EL layer 110b 1, green color organic EL layer 110 b 2 and blue color organic ELlayer 110 b 3 are formed, and organic EL devices respectivelycorresponding to each of the colors of red (R), green (G) and blue (B)are formed.

Cathode 12 is preferably formed using, for example, vapor deposition,sputtering or CVD, while vapor deposition is particularly preferablesince it is capable of preventing damage to organic EL layer 110 bcaused by heat.

In addition, a protective layer of SiO₂ or SiN and so forth may also beprovided on cathode 12 to prevent oxidation.

(Sealing Step)

Finally, substrate 2 on which organic EL devices (light-emittingdevices) are formed is sealed with sealing substrate 3 b (see FIG. 3) bymeans of sealing resin. For example, a sealing resin composed ofthermosetting resin or UV-cured resin is coated onto the peripheraledges of substrate 2 followed by arranging sealing substrate 3 on thesealing resin. The sealing step is preferably carried out in an inertgas atmosphere such as nitrogen, argon or helium gas. If this step iscarried out in air, water, oxygen and so forth penetrate to cathode 12through defects in the case pin holes or other defects are present incathode 12 resulting in the risk of cathode 12 being oxidized andthereby making this undesirable.

Subsequently, together with connecting cathode 12 to the wiring ofsubstrate 2, the wiring of circuit device section 14 (see FIG. 3) isconnected to a drive IC (drive circuit) provided either on or outsidesubstrate 2 to complete the organic EL apparatus 1 of the presentembodiment.

As has been described above, in the present embodiment, sincedeterioration of emission characteristics over time of red and greenlight are adjusted so as to match blue light having the largest degreeof deterioration over time by changing the film thickness of thepositive hole transport layers, even if changes occur over time, thedeterioration over time of each color is the same, thereby making itpossible to maintain a satisfactory emission state without a shift incolor balance. Thus, it is no longer necessary for a consumer toreadjust the white balance after purchase or provide a complex drivecircuit. In addition, in the present embodiment, since theaforementioned deterioration of emission characteristics over time canbe adjusted by a simple constitution and process consisting ofcontrolling the weight or number of liquid droplets when a liquidcontaining a positive hole transport layer material is discharged in theform of liquid droplets, together with the system configuration beingable to be simplified, production efficiency can be improved.

Furthermore, the electro-optical apparatus of the present invention isequipped with a display system in the form of the aforementioned organicEL apparatus (emitter), specific examples of which include, in additionto the aforementioned organic EL apparatus, an inorganicelectroluminescence display, plasma display (PDP) and field emissiondisplay (FED).

EXAMPLE

-   -   a. Positive hole transport layer materials were printed at 10        ng×10 shots onto pixels surrounded by bank sections for R (red),        G (green) and B (blue) pixels, respectively. As a result, the        film thickness of the R, G and B pixels was 60 nm each.    -   b. A light-emitting layer (organic EL layer) was deposited on        the R, G and B pixels, respectively, at 80 nm while in this        state followed by the deposition of a cathode thereon by vacuum        vapor deposition to obtain a light-emitting device.    -   c. As a result of measuring the service life of this device, the        service half-lives of R, G and B were 1800 h for R, 3000 h for G        and 1000 h for B.

However, the time during which white color was obtained was 700 h due toa shift in color balance during white display.

-   -   d. Next, liquid droplets of a positive hole transport layer        forming material were discharged onto the pixels surrounded by        bank sections at 10 ng×8 shots for the R pixel, 10 ng×6 shots        for the G pixel, and 10 ng×10 shots for the B pixel. As a        result, the film thicknesses of the R, G and B pixels were 50 nm        for the R pixel, 45 nm for the G pixels and 60 nm for the blue        pixel.    -   e. Light-emitting layers were deposited at 80 nm for R, G and B,        respectively, while in this state followed by the deposition of        a cathode thereon by vacuum vapor deposition to obtain a        light-emitting device.    -   f. As a result of measuring the service life of this device, the        service half-lives of R, G and B were 1200 h for R, 1300 h for G        and 1000 h for B.

However, the time during which white color was obtained was 940 h. g.Namely, the service life of the panel was demonstrated to be prolongedeven though the service life of each of the colors of red and greendecreased.

(Second Embodiment)

FIG. 9 is a perspective view showing a mobile personal computer as anexample of electronic apparatus equipped with an organic EL apparatus(emitter) of the present invention.

Mobile personal computer 200 is provided with a main unit 202 equippedwith a keyboard 201, and a display unit 203 composed of an organic ELapparatus (emitter) according to the aforementioned first embodiment.

(Third Embodiment)

FIG. 10 is a perspective view showing a cell phone as an example ofelectronic apparatus equipped with an organic EL apparatus (emitter) ofthe present invention.

Mobile telephone 300 is provided with a plurality of operating buttons301, an earpiece 302, a mouthpiece 303 and an organic EL apparatus(emitter) 304 according to the aforementioned first embodiment.

(Fourth embodiment)

FIG. 11 is a perspective view showing a digital still camera as anexample of electronic apparatus equipped with an organic EL apparatus(emitter) according to the present invention. Furthermore, connectionswith external equipment have been simplified.

Digital camera 400 is provided with a case 401, a display panel 402provided on the back and composed of an organic EL apparatus (emitter)according to the aforementioned first embodiment, a light receiving unit403 provided on the viewing side of case 401 (back side in the drawing)containing components such as an optical lens and CCD (charge coupleddevice), a shutter button 404, and a circuit board 405 that transfersand stores image signals of the CCD when shutter button 404 is pressed.This display panel 402 performs display based on image signals generatedfollowing photoelectric conversion from a CCD or other image-capturingdevice.

In addition, video signal output terminals 406 and an input/outputterminal 407 are provided on the side of case 401 in this digital stillcamera 400. As shown in the drawing, a television monitor 500 isconnected to the former video signal output terminals 406, and apersonal computer 600 is connected to the latter data communicationinput/output terminal 407 as necessary to form a constitution in whichimage signals stored in the memory of circuit board 405 are output totelevision monitor 500 or personal computer 600 according topredetermined operations.

Furthermore, the electronic apparatus equipped with an organic ELapparatus (emitter) of the present invention is not limited to thosedescribed above, but rather examples of other electronic apparatusinclude televisions, portable televisions, direct-view video taperecorders equipped with a viewfinder monitor, PDA, portable gamingmachines, car-mounted audio equipment, automobile instrumentation, CRT,car navigation systems, pagers, electronic notebooks, calculators,wristwatches, word processors, workstations, video telephones, POSterminals and equipment equipped with a touch panel.

Although the above has provided an explanation of preferable embodimentsof the present invention with reference to the drawings, it goes withoutsaying that the present invention is not limited to these embodiments.The aforementioned embodiments are intended to indicate examples of theshapes and combinations, etc. of each composite member shown, and hencethe present invention may be altered in various ways based on designrequirements and so forth within a range that does not deviate from thegist of the present invention.

For example, impurity ions (for example, anions such as F⁻, H₂PO₄ ⁻,Cl⁻, NO²⁻, Br⁻, NO₃ ⁻ or SO⁴⁻ or cations such as Li⁺, Na⁺, NH₄ ⁺, K⁺,Ca²⁺, Mg²⁺, Rb²⁺, Cs⁺ or Ba²⁺) may be mixed into one of either thelight-emitting material that composes organic EL layer 110 or thepositive hole transport layer forming material that composes positivehole transport layer 110 a to accelerate the degree of deteriorationover time for a light-emitting unit for which deterioration over time isto be adjusted (accelerated). In this case as well, the degree ofdeterioration over time of each color can be made to be uniform.

In addition, a constitution can also be employed in which the thicknessof cathode 12 is changed (pattemed) corresponding to the light-emittingunit. For example, although cathode 12 is formed from calcium layer 12 aand aluminum layer 12 b, a constitution may be employed in which thecalcium layer having a large resistance is formed to be thicker for alight-emitting unit for which deterioration over time is to be adjusted(accelerated). In this case, since a higher voltage is required as aresult of increasing the resistance, the degree of deterioration overtime can be increased due to decrease in efficiency. In this case,cathode 12 (calcium layer 12 a) serves as an electron donor thatfunctions as a deterioration adjustment unit. Furthermore, in additionto the cathode, the film thickness of the electron injection layer canalso be changed corresponding to the light-emitting unit in the case ofproviding an electron injection layer as another means of adjustingdeterioration of emission characteristics over time with an electrondonor.

Moreover, a constitution can also be employed in which only the banksections corresponding to the light-emitting unit for whichdeterioration over time is to be adjusted (accelerated) can be made toextend from the sealing resin. In this constitution, since the cathodeis oxidized due to the penetration of water, oxygen and so forth fromthe extended bank sections, deterioration over time of thatlight-emitting unit can be accelerated.

1. A manufacturing apparatus of an emitter having a plurality of typesof light-emitting units with different changes in emissioncharacteristics over time, the apparatus comprising a deteriorationadjustment device which adjusts deterioration of the emissioncharacteristics over time in a predetermined type of light-emittingunit.
 2. A manufacturing apparatus of an emitter, according to claim 1,wherein the light-emitting units respectively have a light-emittinglayer and a hole donor which supplies positive holes to thelight-emitting layer, and the thickness of the hole donor is adjusted bythe deterioration adjustment device based on the deterioration ofemission characteristics over time in the predetermined type oflight-emitting unit.
 3. A manufacturing apparatus of an emitter,according to claim 2, the apparatus comprising a discharge device whichforms the hole donor by discharging a liquid containing a hole donormaterial, and wherein the weight or the number of drops of the liquiddischarged from the discharge system is adjusted by the deteriorationadjustment device.